Portable thermoplastic cement dispensers



Sept. 7, 1965 H. c. PAULSEN 3,204,828

PORTABLE THERMOPLASTIC CEMENT DISPENSERS Filed March 16, 1964 rn on m na6P. ma 1 H By his Attarn 63 A! K7615:

United States Patent 3,204,828 PORTABLE THERMOPLASTIC CEMENT DISPENSERSHans C. Paulsen, Lexington, Mass., assignor to United Shoe MachineryCorporation, Boston, Mass., at corporation of New Jersey Filed Mar. 16,1964, Ser. No. 352,002

3 Claims. (Cl. 222146) This invention relates to cement extruders andmore particularly is directed to an improved hand-held device fordispensing thermoplastic adhesive.

Thermoplastic cements have proven to be well suited for a wide varietyof applications and are particularly well suited for applications wheresmall quantities of quick-setting adhesive are required such as inclosing of cartons, in certain shoemaking operations, or in furniturerepairing. For this purpose a number of thermoplastic cement applyingdevices have been developed. In many instances such devices have noself-contained means for melting the adhesive from its solid form, butinstead must be supplied with molten adhesive from a separate devicewhich generally is not easily portable. In most instances where heatingmeans are provided in the tool itself the tool is thereby made bulky andnot easily handled.

Accordingly it is a general object of the invention to provide a simpleand inexpensive portable melting and dispensing tool for thermoplasticcement or the like. To this end and as features of the invention thetool includes a handle and means carried by the handle for holding andguiding a solid block of thermoplastic cement to a melting anddispensing nozzle. One end of the block is exposed and convenientlyplaced so as to be fed to the melting means by force applied by onefinger of the operator.

The above and other features of the invention, including various noveldetails of construction and combinations of parts will now be moreparticularly described with reference to the accompanying drawings andpointed out in the claims. It will be understood that the particulardevice embodying the invention is shown by way of illustration only andnot as a limitation of the invention. The principles and features ofthis invention may be em- .ployed in varied and numerous embodimentswithout departing from the scope of the invention.

In the drawings:

FIG. 1 is a perspective view showing one form of tool embodying theinvention;

FIG. 2 is a section taken substantially along the center line of thetool; and

FIG. 3 is a plan view of a portion of the tool with the handle brokenaway taken along plane IIIIII of FIG. 2.

As illustrated, the device comprises a handle 2 which may be made .ofany suitable non-heat conducting material. The handle is adapted toreceive an electrical heating element 4 having a heat conducting rod 6projecting therefrom. A pair of electrical leads 8 connects the heatingelement 4 with a source of electricity not shown. A heat shield 10 madeof felt or other suitable non-heat conductive material, is disposedabout the handle 2 in the vicinity of the heating element 4 to afiordadditional insulation and protection for the hand of the operator. Aportion 12 of a barrel member 14 is secured to the rod 6 so as to bespaced slightly from the handle 2 with the rod conducting heat from theheating element to the barrel member. The upper portion of the barrelmember 14 receives a tubular sleeve 16 made of a non-heat conductingmaterial. The sleeve 16 is adapted to receive a cylindricalthermoplastic cement block T in solid form and having a diameter snuglyfitting the inside diameter of the sleeve. The sleeve is received in abore 18 in the barrel member 14 and is secured against a shoulder 20 bya screw 22. At one end of the sleeve there is provided in a nozzleportion 24 of the barrel member a cone-shaped melting chamber 26 whichleads into a cylindrical chamber 28 having a spring loaded ball checkvalve 30 at its entrance. A discharge passage 32 leads outwardly fromthe chamber 28.

The handle 2 of the tool is adapted to be held in an operators hand asseen in FIG. 1. It will be noted that the axis of the sleeve forms anangle with the axis of the handle. To dispense molten cement from thepassage 32 a thermoplastic. cement block T, which may conveniently beapproximately three inches in length, is inserted in the sleeve 16. Thelower end of the block is guided by the sleeve into the chamber 26 whereheat conducted through the rod 6 acts to melt only the very end of theblock. The opposite end of the block T projects from the upper end ofthe sleeve 16 where it may be conveniently engaged by an operators thumbas seen in FIG. 1. The sleeve- 16, being non-conductive, permitssubstantial heating of the thermoplastic block T only in the lowerregion of the sleeve. When molten cement is to be dispensed from thepassage 32 the operator pushes the block T into the sleeve 16. As itmoves along the sleeve, the block acts as a piston upon the moltencement in the melting chamber 26 and the pressure thus generated forcesthe cement through the spring loaded check valve 30, and through thedischarge passage 32 for application to a work piece.

As additional melted cement is required the operator pushes thethermoplastic block T further into the sleeve 16 so that the end of theblock is progressively melted in the chamber 26 and additional moltencement is forced from the discharge passage 32. To stop the flow ofcement from the passage 32 the operator removes his thumb from the blockT and the spring loaded ball check valve 30 prevents further flow fromthe chamber 26. A recess 34 is provided in one side of the sleeve 16 sothat as the block T is used it may be urged into the sleeve 16sufiiciently to enable another thermoplastic block to be inserted andguided by the sleeve.

While I have shown and described a preferred form of my inventionparticularly directed to the dispensing of thermoplastic cement, it isobvious that thermoplastic materials other than cement could bedispensed and that various changes may be made in the construct-ion ofthe tool by those skilled in the art, without departing from the spiritof the invention as defined in the patent claims.

Having thus described my invention what I claim as novel and desire tosecure by Letters Patent of the United States is:

1. A device for dispensing molten thermoplastic material comprising abarrel member shaped to provide a melting chamber and a dischargepassage leading outwardly therefrom, a sleeve secured to the barrelmember and extending inwardly toward the melting chamber and extendingoutwardly from the barrel member, the sleeve being adapted to receive acomplementarily shaped block of solid thermoplastic material with oneend in the melting chamber and the other end projecting beyond the endof the sleeve remote from the melting chamber, a handle projecting fromthe barrel member, a means for heating the barrel member so that theleading end of the block of thermoplastic material will be progressivelymelted in the chamber and molten material extruded through the dischargepassage as the block is pushed along said sleeve and into the meltingchamber, said sleeve being relatively short in length with respect tothe length of said handle, the end of said sleeve remote from themelting chamber being closely adjacent said handle, and the axis of saidsleeve and the aXis of said handle intersecting so as to form an anglesuch that an operator can grip the handle with the fingers of one handwhile engaging the outer end of the block with the thumb of said hand topush the References Cited by the Examiner block through the sleeve andinto the melting chamber as UNITED STATES PATENTS a result of said closead acency and said angulanty of the aXes 2,054,506 9/36 Leltsch 228-532. A device according to claim 1 in which the sleeve 5 2I118:415 5/38Pesark 120116 is formed of a substantially non-heat conducting material.2,380,138 7/45 Abramson 15504 3. A device according to claim 1 in whichthe outer 2556509 6/51 Arkless 219227 2,979,234 4/61 Kam'borian 222-146end of the sleeve is cut away on its side adjacent the handle to providea space through Which the outer end of the thermoplastic block may beengaged by the operators 1O RAPHAEL LUPO Primary Examiner thumb.

1. A DEVICE FOR DISPENSING MOLTEN THERMOPLASTIC MATERIAL COMPRISING ABARREL MEMBER SHAPED TO PROVIDE A MELTING CHAMBER AND A DISCHARGEPASSAGE LEADING OUTWARDLY THEREFROM, A SLEEVE SECURED TO THE BARRELMEMBER AND EXTENDING INWARDLY TOWARD THE MELTING CHAMBER AND EXTENDINGOUTWARDLY FROM THE BARREL MEMBER, THE SLEEVE BEING ADAPTED TO RECEIVE ACOMPLEMENTARILY SHAPED BLOCK OF SOLID THERMOPLASTIC MATERIAL WITH ONEEND IN THE MELTING CHAMBER AND THE OTHER END PROJECTING BEYOND THE ENDOF THE SLEEVE REMOTE FFROM THE MELTING CHAMBER, A HANDLE PROJECTING FROMTHE BARREL MEMBER, A MEANS FOR HEATING THE BARREL MEMBER SO THAT THELEADING END OF THE BLOCK OF THERMOPLASTIC MATERIAL WILL BE PROGRESSIVELYMELTED IN THE CHAMBER AND MOLTEN MATERIAL EXTRUDED THROUGH THE DISCHARGEPASSAGE AS THE BLOCK IS PUSHED ALONG SAID SLEEVE